Brake for an electric drive motor

ABSTRACT

A drive motor comprises a motor body (5) for rotating a motor shaft (11) in a predetermined forward direction; a brake engagement surface (30) formed at a projection (14) which is projected from a part of the motor shaft; claw piece (15) which engages with the projection at a predetermined position on interruption of electricity for the motor body and acts to stop rotation of the motor shaft, wherein the claw piece comprises an engagement claw (60) of actue angle shape; and a wedge engagement release mechanism (31) for releasing the wedged engagement by rotating the motor shaft in a release direction which is equal to the reversed direction.

Background of the Invention

This invention relates to a drive motor which can be perfectly stoppedjust on interruption of electricity and also relates to a coin feedingdevice which can be rotatable in reverse direction with such a drivemotor.

Conventionally, a drive motor of the type described comprises, asillustrated in FIGS. 4 and 5, a motor body 5, a transmission 6, and amotor shaft 11. On being applied to a coin feeding device, the motorbody 5 drives the coin feeding device by means of the motor shaft whichis rotatable in counterclockwise direction through the transmission 6.Such drive motor is disclosed in, for example, Japanese Patent ExaminedPublication No. 55-48634.

A coin feeding device comprises a coin hopper 1 where a plurality ofcoins are received. In the hopper 1, a coin feeding disc 2 is rotatablydisposed on a base plate 3. The coin feeding disc 2 is rotated by themotor shaft 11 through the transmission 6, thereby a coin is fed. Thenumber of the fed coins is counted by a counting microswitch. When thenumber of the fed coins is reached to a predetermined one, theelectricity to the drive motor is immediately interrupted.Simultaneously, rotation of the motor shaft 11 is stopped by a brakemechanism 8 described below so that feeding of overabundant coins areprohibited.

Referring to FIG. 5, the brake mechanism 8 comprises a projectionassembly and a break engagement assembly. The projection assemblyconsists of a brake wheel 13 and a plurality of projections 14. Thebrake wheel 13 is made of synthetic resin and is attached to the motorshaft 11 so as to be rotated with the motor shaft 11. The projections 14are integrally formed with the brake wheel 13, being equally apart fromeach other, on the perimeter thereof.

The brake engagement assembly comprises a claw piece 15 having a clawtip 18, a pivot pin 16, a spring 17, a release iron piece 19, a pivotaxis 20, an attracted portion 21, a release piece 23, and a lower end 24of the release iron piece. The claw tip 18 can be engaged with theprojections 14. The pivot pin 16 is for use in pivotally supporting oneend of the claw piece 15 to a stator 9 of the motor body 5. The clawpiece 15 is always forced towards the projections 14 by the spring 17.The release iron piece 19 extends along an outer surface 22 of thestator 9. The pivot axis 20 is used for pivotally supporting one end ofthe release iron piece 19 to the stator 9. On the other end of therelease iron piece 19, the attracted portion 21 is disposed which isattracted to the stator 9 when the motor body 5 is energized. Therelease piece 23 downwardly extends from the release iron piece 19 onits side facing to the attracted portion 21. The lower end 24 of therelease iron piece contacts with a supporting shoulder 25 at the freeend of the claw piece 15.

When a exciting coil 26 of the motor body 5 is energized, the attractedportion 21 is attracted to the outer surface 22 of the stator 9 due tomagnetic attraction action of the stator 9. As a result, the releaseiron piece 19 is rotated in a clockwise direction around the pivot axis20, thereby the lower end 24 of the release piece 23 pushes thesupporting shoulder 25 of the claw piece 15 down against the springforce of the spring 17. The claw tip 18 of the claw piece 15 is out ofengagement with one of the projection 14 of the break wheel 13.Accordingly, the motor shaft 11 is maintained in a rotatable condition.

On the other hand, when the electricity to the exciting coil 26 of themotor body 5 is interrupted, no magnetic attraction action to theattracted portion 21 of the stator 9 is generated. As a consequence, theclaw piece 15 is pushed towards the outer surface of the break wheel 13by the spring force of the spring 17. Accordingly, the claw tip 18 ofthe claw piece 15 engages with one of the projections 14 at apredetermined engagement position, thereby the motor 10 is preventedfrom rotating and the rotation of the motor shaft 11 is stopped.Simultaneously, the coin feeding disc 2 is also stopped from rotationand no coins are fed out.

Description will be made below regarding to a conventional coin feedingdevice.

A conventional coin feeding device generally comprises, as shown inFIGS. 4, 11, and 12, a hollow cylindrical case 52 disposed at the lowerend of the hopper 1, an outlet 53 provided at the lower end of the upperportion of surrounding surface of the hollow cylindrical case 52, a baseplate 3, the coin feeding disc 2 disposed on the base plate 3, coinreceiving holes 54, coin feeding arms 55, an outlet guiding member 56,and an outlet guiding pin 57. The hopper 1 defines a reception space forreceiving a plurality of coins. The base plate 3 defines the bottom ofthe hollow cylindrical case 52. The coin feeding disc 2 is rotated bythe motor shaft 11 of the drive motor due to its rotation. Each of thecoin receiving holes 54 is penetrated through the coin feeding disc 2and guides a coin A to the base plate 3. The coin feeding arms 55 aredisposed between the coin feeding disc 2 and the base plate 3, beingradially elongated to a circumference obtained by lacing anapproximately center or the coin receiving holes 54. Each of the coinfeeding arms 55 rotates accompanying with rotating coin feeding disc 2and feeds the coin A to the outlet 53 by sliding thereof on the baseplate 3. The outlet guiding member 56 is disposed between the coinfeeding disc 2 and the base plate 3 at the downstream of the outlet 53and guides the coin A delivered by the coin feeding arms 55 into theoutlet 53. The outlet guiding pin 57 is provided on the base plate 3 andguides the coin A delivered by the coin feeding arms 55 to the outlet 53in corporation with the outlet guiding member 56.

A scraper 59 has a plurality of coin feeding wings or fingers which isequal in number to the coin receiving holes 54 of the coin feeding disc2. The scraper 59 rotates on the base plate 3 in synchronism with thecoin feeding disc 2. Each of the coin feeding wings or fingers 58 feedsthe coin A delivered by the outlet guiding member 56 and the outletguiding pin 57 towards the outlet 53.

In the above-mentioned conventional brake mechanism, the claw tip of theclaw piece is elastically forced to the brake wheel by means of thespring and is engaged with the projection to ensure braking. However,the claw tip is elastically pushed aside by the inertially rotatedprojections of the break wheel due to the inertia force on breaking.This results in incomplete breaking for the coin feeding disc.

It is especially true with the increased inertia force on breaking forthe purpose of increasing the rotation speed of the drive motor, or withthe worn claw and reduced spring force of the spring, because in suchconditions the claw and the projections are readily pushed aside.Accordingly, it becomes difficult to completely stop the coin feedingdisc at a predetermined engagement position and overabundant coins arethrown out.

On the other hand, in the above-mentioned conventional coin feedingdevice, the coin feeding disc is rotated in the reverse directionaccompanying with the reversed rotation (in clockwise direction) of themotor shaft caused by the reversed rotation of the motor. In this event,the coin delivered from the coin receiving hole to the base platecollides with the outlet guiding member and the outlet guiding pin.Accordingly, the coin is caught between the outlet guiding member withthe outlet guiding pin and the coin feeding arms and is fixedtherebetween. This causes interruption of reversed rotation of the coinfeeding disc, and in turn, that of the motor shaft.

It is therefore a principle object of the present invention to provide adrive motor of which motor shaft can be completely stopped even when theinertia force after breaking in increased, or when the claw is worn andthe spring force of the spring is reduced after long use, with respectto the above mentioned problem caused to the drive motor.

It is another object of the present invention to provide a coin feedingdevice which allows reversed rotation of the coin feeding disc and themotor shaft without causing the coin being caught between the outletguiding member with the outlet guiding pin and the coin feeding arms andfixed therebetween, with respect to the above mentioned problem causedin the coin feeding device.

Other objects and advantages of the present invention will be clear asthe description proceeds.

SUMMARY OF THE INVENTION

According to the present invention, a drive motor which comprises amotor body for rotating a motor shaft in a predetermined direction; aprojection assembly which is provided so as to be projected from aportion of said motor shaft; and a break engagement assembly whichengages with said projection member at a predetermined position oninterruption of electricity for said motor body and acts to stoprotation of said motor shaft; wherein said brake engagement assemblycomprises an engagement claw of acute angle shape, and said projectionassembly comprises a wedge engagement surface where said engagement clawis engaged in a wedged manner.

BRIEF DESCRIPTION OF DRAWINGS

For a better understanding of the invention as well as other objects andfurther features thereof, reference is made to the following detaileddescription to be read in conjunction with the accompanying drawings,wherein:

FIG. 1 is a perspective view of a drive motor according to a firstembodiment of the present invention;

FIG. 2 is a front view of a motor body of a drive motor according tosaid first embodiment of the present invention, in which an excitingcoil is energized;

FIG. 3 is a front view of a motor body of a drive motor according tosaid first embodiment of the present invention, in which an excitingcoil is not energized;

FIG. 4 is a partial side view showing a combination of a drive motor anda coin feeding device;

FIG. 5 is a front view of a motor body of a conventional drive motor, inwhich an exciting coil is not energized,

FIG. 6 is a front view of a motor body of a conventional drive motor, inwhich an exciting coil is energized;

FIG. 7 is a sectional view showing the structure of a rotor and a motorshaft in a drive motor according to a second embodiment of the presentinvention;

FIG. 8 is a sectional view of an outlet guiding member in a coin feedingdevice according to a third embodiment of the present invention;

FIG. 9 is a sectional view of another outlet guiding member in a coinfeeding device according to said third embodiment of the presentinvention;

FIG. 10 is a sectional view of an outlet guiding pin in a coin feedingdevice according to said third embodiment of the present invention;

FIG. 11 is a partial front view of a conventional coin feeding device;and

FIG. 12 is a partial perspective view of an outlet guiding member in aconventional coin feeding device.

DETAILED DESCRIPTION OF THE INVENTION

Next, description will be made as regards some embodiments of thepresent invention with reference to the drawing.

Referring to FIGS. 2 and 3, description will proceed in relation to adrive motor according to a first embodiment of the present invention.The drive motor illustrated in FIGS. 2 and 3 comprises similar partsdesignated by like reference numerals as in FIGS. 4, 5 and 6.Description of such parts will be omitted for the purpose of brevity ofthe description.

A brake mechanism 8 in the drive motor consists of a break engagementassembly and a projection assembly. The break engagement assemblycomprises a claw piece 15 which is made of synthetic resin. Awedge-shaped engagement claw 66 is formed at the top of the claw piece15. In the projection assembly, a plurality of projections 14 are formedon the outer surface of the brake wheel. Each of the projections 14 hasa wedge engagement surface 30. The wedge engagement surface engages in awedged manner with the wedge-shaped engagement claw 68.

Referring to FIG. 3, an angle 0 between the extending surface "a" whichextends along the wedge engagement surface 30 and the surface "b" lyingon the top of the wedge-shaped engagement claw 68 along the radius ofthe motor shaft 11 is preferably in the range of 10 to 45 degrees.

When the electricity for the exciting coil 26 of the motor body 5 isinterrupted, the magnetic attraction action to the attracted portion 21of the stator 9 ceases. As a result, the claw piece 15 is forced againstthe outer surface of the brake wheel 13 due to the spring force of thespring 17. The wedge-shaped engagement claw 68 of the claw piece 15engages with the wedge engagement surface 30 at a predeterminedengagement position, thereby rotation of the rotor is stopped. Then,rotation of the motor shaft 11 is stopped. Simultaneously, the coinfeeding disc 2 also escapes from rotation and no overabundant coin isthrown out.

Wedge engagement allows the wedge-shaped engagement claw 68 to engagewith the wedge engagement surface 30 of one of the projections 14.Accordingly, the claw piece 15 is not pushed away even when the motorshaft 11 rotates at relatively high speed and the rotation of the motorshaft 11 is completely stopped.

Turning to FIG. 7, description will proceed regarding to a drive motoraccording to a second embodiment of the present invention.

The drive motor according to the second embodiment utilizes the rotor 10and the motor shaft 11 as disclosed in Japanese Utility ModelPublication No. 63-49802 to the same applicant as the present invention.

The rotor 10 is rotatably attached to the motor shaft 11 of the motorbody 5 through a rotor bearing 37. A first frictional plate 39 isinserted between a rotor supporting plate 38 secured to the motor shaft11 and one end 10a of the rotor 10. Similarly, a second frictional plate40 is inserted between the brake wheel 13 and the other end 10b of therotor 10. On the other hand, a brake spring 43 is inserted between acollar 42 secured to the motor shaft 11 and the break wheel 13. By thespring force of the brake spring 43, the supporting plate 38 and thebreak wheel 13 are forced against both ends 10a and 10b of the rotor 10through the first and second frictional plate 39 and 40, thereby themotor shaft 11 rotates simultaneously with the rotor 10.

Accordingly, when the electricity for the exciting coil 26 of the motorbody 5 is interrupted and the wedge-shaped engagement claw 68 of theclaw piece 15 engages with the wedge engagement surface 30 at apredetermined engagement position, thereby rotation of the rotor 10 isstopped, a stress which is larger than the spring force of the breakspring 43 is caused when the rotation of the motor shaft is stopped.Therefore, drive linkage between the motor shaft 11 and the rotor 10 isseparated. In addition, the rotation by the inertia force caused by therelatively large rotor 10 is not transmitted to the motor shaft 11.Accordingly, more complete breakdown of rotation of the motor shaft 11can be achieved by means of wedge engagement.

Referring to FIGS. 1, 2, and 3, description will now proceed regardingto the first embodiment according to the present invention.

The drive motor according to the third embodiment of the inventionrelates to a wedge engagement release mechanism 31. The wedge engagementrelease mechanism 31 releases, after rotation of the motor shaft 11 isstopped, the wedge engagement between the wedge-shaped engagement claw68 and the wedge engagement surface 30 as described in conjunction withthe first and second embodiments, thereby subsequent rotation operationof the motor shaft 11 is rapidly started.

The wedge engagement release mechanism 31 integrally formed with one endof the motor shaft 11 comprises a release arm 32, iron pieces 34, a ring36, and a permanent magnet pieces 33. The release arm 32 is made ofsynthetic resin and is projected in radius direction of the motor shaft11. The iron pieces 34 is a first ferromagnetic element, attached to thefree ends of the release arm 32. The ring 36 is made of synthetic resinand is supported by a supporting arm 35 on the stator 9 of the motorbody 5. The ring 36 defines rotation orbit for the iron pieces 34. Thepermanent magnet pieces 33 is attached to the ring 36.

The permanent magnet pieces 33 are attached to the ring 36 in a positionsuch that the permanent magnet pieces 33 can rotate, in corporation withthe iron pieces 34, the release arm 32 in a reverse direction from theengagement position where the wedge-shaped engagement claw 68 and thewedge engagement surface 30 engage with each other.

Either one of the permanent magnet pieces 33 and the iron pieces 34 maybe replaced with the other. In addition, the iron pieces 34 may besubstituted by a permanent magnet to rotate the release arm 32 in areverse direction by means of the magnetic attraction action orrepulsion.

When the electricity for the exciting coil 26 of the motor body 5 isinterrupted, the magnetic attraction action to the attracted portion 21of the stator 9 ceases. As a result, the claw piece 15 is forced againstthe outer surface of the brake wheel 13 due to the spring force of thespring 17. The wedge-shaped engagement claw 68 of the claw piece 15engages with the wedge engagement surface 30 at a predeterminedengagement position, thereby rotation of the rotor is stopped. Then,rotation of the motor shaft 11 is stopped. Simultaneously, the coinfeeding disc 2 also escapes from rotation and no overabundant coin isthrown out.

However, rotation of the motor shaft 11 by the electricity is stoppedand the force of inertia comes into play, causing further rotation ofthe motor shaft 11, the wedge engagement release mechanism 31 of thisembodiment is operated. The iron pieces 34 is attracted by the permanentmagnet pieces 33. This results in rotation of the motor shaft 11 in areversed direction at a predetermined distance. More particularly, theprojections 14 are retracted to a position as depicted by the dashedline in FIG. 3. Therefore, the wedge-shaped engagement claw 68 is out ofengagement with the wedge engagement surface 30.

As a result, when the motor body 5 is energized after the motor shaft 11is once stopped, the release iron piece 19 is rotated around the pivotaxis 20 in a clockwise direction. The lower end 24 of the release piece33 pushes the supporting shoulder 25 of the claw piece 15 down againstthe spring force of the spring 17. The wedge engagement claw 18 of theclaw piece 15 is immediately released to outside of the orbit of theengagement surface 30. That is, the wedge engagement claw 18 is releasedfrom the projection 14. Therefore, the motor shaft 11 is maintained tobeing rotated.

Referring to FIGS. 8, 9, and 10, description will be made regarding to acoin feeding device according to the third embodiment of the presentinvention.

The coin feeding device in accordance with the third embodiment of thepresent invention relates to improvements of the outlet guiding member56 and the outlet guiding pin 57, which allow smooth rotation of themotor shaft 11 in a reverse direction. This coin feeding device isapplied in combination with the wedge engagement release mechanism 31 ofthe above mentioned third embodiment according to the present invention.

As shown in FIG. 8, when the coin feeding disc 2 rotates in a reversedirection, the outlet guiding member 56 collides with a coin A deliveredfrom the coin feeding hole to the base plate 3. However, the outletguiding member 56 is provided with a first riding surface 61, which isinclined from the bottom to the top, at a position where it collideswith the coin, thereby the coin is ride on the riding surface 61.

The coin can be readily ride on the first riding surface 61 because thesurface is penetrating through the base plate 3.

As shown in FIG. 9, the base plate may provided with a convex 62 forreceiving the lower end of the first riding surface 61.

Referring to FIG. 10, when the coin feeding disc 2 rotates in a reversedirection, the outlet guiding pin 57 collides with a coin A deliveredfrom the coin feeding hole to the base plate 3. However, the outletguiding member 57 is provided with a second riding surface 63, which isinclined from the bottom to the top, at a position where it collideswith the coin, thereby the coin A is ride on the riding surface 63.

Thus, when the motor shaft 11 of the drive motor rotates in a reversedirection (clockwise direction), the coin feeding disc 2 also rotates ina reverse direction. In this case, the coin A delivered from the coinreceiving hole 54 to the base plate 3 collides with the outlet guidingmember 56 and the outlet guiding pin 57. However, the first and secondriding surfaces 61 and 63 contribute to the riding of the coin so thatthe rotation of the coin feeding disc 2 in a reverse direction can beallowed and the reversed rotation of the motor shaft 11 becomespossible.

As a result, the motor shaft 11 is rotated in a reverse direction at apredetermined distance by the wedge engagement release mechanism 31,thereby the projections 14 are retracted and the engagement between thewedge-shaped engagement claw 68 and the wedge engagement surface 30 isreleased.

As described above, according to the present invention, a drive motorcan be provided of which motor shaft can be completely stopped even whenthe inertia force on breaking in increased, or when the claw is worn andthe spring force of the spring is reduced after long use, with respectto the above mentioned problem caused to the drive motor.

In addition, according to the present invention, a coin feeding devicecan be provided which allows for the reversed rotation or the coinfeeding disc and the motor shaft without causing the coin to be caughtbetween the outlet guiding member with the outlet guiding pin and thecoin feeding arms and fixed therebetween, with respect to the abovementioned problem caused by the coin feeding device.

What is claimed is:
 1. An electrically operable drive motor comprising:amotor body for rotating a motor shaft in a predetermined direction; amember projecting from one side portion of said motor shaft; brakeengagement means disposed for engaging said projecting member at apredetermined position upon interruption of electricity for driving saidmotor;said brake engagement means comprising an engagement claw shapedat an acute angle and being adapted to stop the rotation of said motorshaft; said projecting member having a wedge engagement surface forcooperative engaging said brake engagement means in a wedged manner; awedge engagement release means for releasing said wedged engagement whenengaged by rotating said motor shaft in a direction opposite to itspredetermined direction;said wedge engagement release means comprising amagnetically responsive release arm member projecting from an oppositeportion of said motor shaft and adapted for movement along apredetermined orbit;and a magnetic drive member for magneticallyreleasing said arm member.
 2. The drive motor as in claim 1, whereinsaid release arm member has a first magnetic element made of aferromagnetic material,said magnetic drive member comprising a secondmagnetic element also made of ferromagnetic material disposed opposed tosaid first magnetic material outside of said orbit, wherein said firstand second magnetic members are adapted cooperatively to rotate saidrelease arm member.